1. Field of the Invention
The present invention relates to a spring manufacturing apparatus and a manufacturing method of the same and, more particularly, to a spring manufacturing apparatus for manufacturing a compression coil spring, a tension coil spring, a torsion coil spring, and the like, and a manufacturing method of the same.
2. Description of the Related Art
A conventional spring manufacturing apparatus requires a tool called a quill for guiding a wire, which is to be formed into a spring, to a predetermined position. This quill is constituted by a liner portion having a hole through which a wire is guided from a wire supply position to a spring forming position, and a wire guide for feeding out the wire from the front end of the liner and the fed wire is formed to a desired spring shape by using a tool used for bending, curving, or cutting.
A conventional spring manufacturing apparatus using a quill of this type, for example, one disclosed in Japanese Patent Laid-Open No. 54-52662 is known. In this apparatus, a support is mounted on an outer portion of a wire guide. The support is set to be rotatable about the hole of the wire guide as the center. The support is rotated in an interlocked manner with the projecting and retracting movements of a tool, which is used for bending, curving, or cutting the wire and projects and retracts toward and from the front end of the wire guide, so that the tool will not collide against the support. Therefore, the completed coil spring will not have a linear portion at its starting distal end, a sharply bent portion at its trailing distal end, and the like.
Also, another conventional spring manufacturing apparatus disclosed in Japanese Patent Laid-Open No. 54-52661 is known. According to this disclosure, a tool stop is mounted to a support which is rotatable with respect to a wire guide. This support is rotated in an interlocked manner with the projecting and retracting movements of the tool, so that the tool will not collide against the support. Therefore, the rate of non-defective articles is increased, and variations in the articles are suppressed.
However, in the conventional apparatuses having the above arrangements, the quill serving as a wire guide has a liner portion and a guide portion that are combined with each other. Since the liner portion requires a certain degree of length to guide the wire, the size of the quill itself is increased, and the size of the entire apparatus including the support is increased.
When an apparatus is constituted to have a rotatable quill, the larger the liner length, the higher the torsion stress applied by rotation of the quill to the wire inserted in the liner portion. Then, adverse effects, e.g., variations, occur in the completed articles due to the torsion stress.
The front end of a guide portions of the conventional quills have different shapes depending on desired spring shapes. If, e.g., many types of springs are to be manufactured, the quill must be exchanged by the operator, a very cumbersome operation, and the user must prepare quills having various shapes of the front end in stock. This leads to an increase in manufacturing cost.
In the conventional quill, when the wire is stuck in the liner portion, the stuck wire cannot be removed and thus the quill cannot be re-used.